Method and Apparatus for Using a Probe UE to Measure Interference Using Dynamic Time Division Duplex (TDD) Configuration

ABSTRACT

A probe device and method for measuring TDD interference from neighboring networks in an Enterprise Network (EN). The probe device is situated on a campus of an EN in a position for measuring TDD interference between a neighboring wireless network. The probe device measures TDD interference data and provides it to an Enterprise Network and Orchestrator, which determines the TDD configuration used by neighboring networks, and can take action to mitigate or resolve interference effects from neighboring networks. The probe UE has a TDD measurement unit that may include an SIB Measurement unit for receiving broadcast SIBs signals from neighboring networks, a UL SINR Measurement Unit, a DL SINR Measurement Unit, and a UL RSSI Measurement Unit. The probe device may be positioned in a fixed location in an Enterprise Network campus, and connected to an external power supply.

PRIORITY CLAIM

Reference is made, and priority is hereby claimed to co-pending U.S.Provisional Patent Application No. 63/307,507 filed Feb. 7, 2022,entitled Dynamic Time Division Duplex (TDD) Configuration in a CitizensBroadband Radio Service (CBRS) Network, which is incorporated herein byreference in its entirety.

BACKGROUND Technical Field

The disclosed method and apparatus relate generally to wirelesscommunications networks and more particularly to systems for mitigatinginterference by coordinating spectrum allocated to user devices in thewireless network.

Background

The wireless industry has experienced tremendous growth in recent years,with rapidly improving technology, and faster and more numerousbroadband communication networks are being installed around the globe.Wireless networks have now become key components of a worldwidecommunication system that connects people and businesses at speeds andon a scale unimaginable just a couple of decades ago.

In wireless networks, multiple mobile devices are served voice services,data services, and many other services over wireless connections. So,they may remain mobile while still connected.

Communication Network Configurations

FIG. 1 is an illustration of a basic configuration for a communicationnetwork 100, such as a “4G LTE” (fourth generation Long-Term Evolution)or “5G NR” (fifth generation New Radio) network. Through this networkconfiguration, user equipment (UE) 101 can connect to External PacketData Networks (PDNs) 103 and access any of a variety of services such asthe Internet, Application Servers, Data Services, Voice Services, andothers.

UEs, BS/APs, RAN

“UEs”, or “devices”, or “UE devices” can be used to refer to a widerange of user devices having wireless connectivity, such as a cellularmobile phone, an Internet of Things (IOT) device, virtual realitygoggles, robotic devices, autonomous driving machines, smart barcodescanners, and communications equipment including desktop computers,laptop computers, tablets, and other types of personal communicationsdevices. In the illustration of FIG. 1 , the UEs 101 include a firstmobile phone 101 a, a second mobile phone 101 b, a laptop computer 101 c(which is portable), and a printer 101 d (typically situated at a fixedlocation).

The UEs 101 connect wirelessly over radio communication links 105 to aRadio Access Network (RAN) 107 that typically includes multiple basestation/access points (BS/APs) 109. One of the advantages of suchwireless networks is their ability to provide communications to and frommultiple wireless devices and provide these wireless devices with accessto a large number of other devices and services even though the devicesmay be mobile and moving from location to location.

The term ‘BS/AP” is used herein to include Base Stations and AccessPoints. The BS/APs may include an evolved NodeB (eNB) of an LTE networkor gNodeB of a 5G network, a cellular base station (BS), a CitizensBroadband Radio Service Device (CBSD) (which may be an LTE or 5Gdevice), a Wi-Fi access node, a Local Area Network (LAN) access point,and a Wide Area Network (WAN) access point.

Core Network

The RAN 107 connects the UEs 101 with the Core Network 111, whichprovides an interface between the RAN 107 and other networks. The CoreNetwork can have multiple functions; in one important function, the CoreNetwork 111 provides access to other devices and services either withinits network, or on other networks such as the External PDNs 103.Particularly, the UEs 101 are wirelessly connected to the BS/APs 109 inRAN 107, and the RAN 107 is coupled to the Core Network 111 utilizingany appropriate communication means, such as wireless, cable, and fiberoptic. Thus, the RAN 107 and the Core Network 111 provide a system thatallows information to flow between a UE in the cellular or privatenetwork and other networks, such as the Public Switched TelephoneNetwork (PSTN) or the Internet.

In addition to providing access to remote networks and allowinginformation to flow between the cellular network and the external PDNs103, the Core Network 111 includes RAN Control Units 113 that manage thewireless network and provide control of the air interface between theBS/AP 119 and the UEs 101. The Core Network 111 may also coordinate theBS/APs 109 to minimize interference within the network.

CBRS Networks

One type of wireless network that recently became available for generaluse by enterprise locations is a Citizen's Broadband Radio Service(CBRS) network, which utilizes the CBRS radio band of 3550-3700 MHz,nominally divided into fifteen channels of 10 MHz each. Particularly,the US Federal Government recently approved use of the CBRS band of thefrequency spectrum and finalized rules (Rule 96) that allow generalaccess to the CBRS band. The CBRS rules set forth detailed requirementsfor the devices that operate in a CBRS network and how they communicate.CBRS supports both LTE and 5G devices. CBRS provides enormous wirelessnetworking power to organizations that have never had such an optionbefore and opens up and creates opportunities for a range of newapplications.

FIG. 2 is a diagram of an example of a CBRS wireless communicationnetwork 200. In FIG. 2 , a plurality of BS/APs 202 are deployed within alocation 203 on the enterprise's campus, providing service to aplurality of UEs 204.

In FIG. 2 , each BS/AP 202 has a range that represents its respectivewireless coverage. A first UE 202 a is wirelessly connected to a firstBS/AP 204 a, which is providing service to it. A second UE 204 b iswirelessly connected to a second BS/AP 202 b and is providing service tothat second UE 204 b. Other UEs 204 connect to their respective BS/APs,for example third UE 204 c, fourth UE 204 d, fifth UE 204 e, sixth UE204 f, and seventh UE 204 g are shown in the enterprise location 203.All the BS/APs are connected to an operator Core Network 222 by anyappropriate communication means, such as wire, fiber optic, wirelessradio and/or a PDN 220. The operator Core Network 222 includescomponents such as an OAM Server 207, a SON assist unit 208, a DomainProxy 209, an Automatic Configuration Server (ACS) 210, a LocationDatabase 211, and other databases 212, all of which are connected toeach other within the operator Core Network 222 by any appropriatemeans.

Base stations (BS/APs) within a CBRS network are termed “CBSDs”, and UEsare termed End User Devices (EUDs). CBSDs are fixed Stations, ornetworks of such stations, that operate on a Priority Access License(PAL) or General Authorized Access (GAA) basis in the CBRS consistentwith Title 47 CFR Part 96 of the United States Code of FederalRegulations (CFR).

SAS

The Operator Core Network 222 is connected to a Spectrum Access System(SAS) 232, which is connected to a Spectrum Database 233 that includesdata regarding the spectrum that it is managing. Collectively, the SAS232 and the Spectrum Database 233 are referred to as a SpectrumManagement Entity (SME) 234. The SAS 232 provides a service, typicallycloud-based, that manages the spectrum used in wireless communicationsof devices transmitting in the CBRS band in order to prevent harmfulinterference to higher priority users, such as the military and prioritylicensees. The CBRS rules require that the SAS 232 allocate spectrum tothe CBSDs to avoid interference within the CBRS band. To allocatespectrum and maintain communication between the CBSDs and the SAS 232, aseries of messages are exchanged for purposes including registration,spectrum inquiry, grant, and heartbeat response. In a RAN that hasmultiple CBSDs, the Domain Proxy (DP) 209 may be implemented tocommunicate with the SAS and manage all transactions between the CBSDsand the SAS 232. The Spectrum Sharing Committee Work Group 3 (for CBRSProtocols) has established an interface specification for registering aCBSD with an SAS 232, requesting a grant of spectrum, and maintainingthat grant. These message flows are described in the document titled“Signaling Protocols and Procedures for Citizens Broadband Radio Service(CBRS): Spectrum Access System (SAS)—Citizens Broadband Radio ServiceDevice (CBSD) Interface Technical Specification”, DocumentWINNF-TS-0016-V1.2.4, 26 Jun. 2019. A CBRS device (CBSD) needsauthorization from the SAS before starting to transmit in the CBRS band.Even after authorization, the SAS may suspend or terminate authorizationof one or more the channels previously authorized. PAL CBSDs (i.e.,CBSDs that operate under a PAL) have higher priority to access theavailable CBRS spectrum than do GAA CBSDs.

TDD and the Co-Existence Manager

The CBRS Alliance (CBRSA) is a standards group for CBRS wirelesscommunication systems. The CBRSA requires that each deployment select aTDD configuration for the CBSDS in the deployment. The CBSDs (and/or theDP) vote to select a TDD configuration with a CxM (the coexistencemanager). FIG. 2 shows a CxM 240 connected to the operator core network222 and an SAS 232 In some embodiments the CxM will be integrated andsupported with SAS implementations. Together the CxM and the SAS may becalled the CSAS.

The CBSDs vote for a TDD config. TDD config selection occurs onlyamongst GAA CBSDs. PAL co-existence is addressed in Point Release 4.1.

The main use focus is on TDD Configs 1 and 2. Generally, config 2 isselected for DL-centric deployments, whereas config 1 is selected forUL-centric deployments. Both LTE (4G) and NR (5G) utilize TDD configs,and therefore they must be selected. Furthermore, LTE deployments willneed to contend with neighboring NR deployments and vice versa. Foroutdoor CBSDs, aligning 1) cell phases and 2) TDD Configurations is arequirement. For indoor CBSDs, power levels are comparable to UE powerlevels, and the restriction on utilizing the same TDD Configuration maybe relaxed.

All LTE-TDD CBSDs and NR-TDD CBSDs that are part of the same TDDConfiguration Connected Set (TCCS) will use the same TDD Configurationor Equivalent TDD Configurations, when requested by the CxM. Any LTE-TDDConfiguration or the NR Equivalent TDD Configuration may be used,provided all the LTE-TDD and NR-TDD CBSDs in the TDD ConfigurationConnected Set use the same TDD Configuration or Equivalent TDDConfigurations.

FIGS. 3A to 3E are tables that show definitions relating to TDDconfigurations for 4G and 5G communications. For 4G, FIG. 3A shows LTETDD configurations and FIG. 3B shows EutraTddConfigObject Definitions.The subframes 0-9 shown in FIG. 3A indicate whether Uplink (U) orDownlink (D) communications are allowed in the slot. A slot is used byscheduling mechanisms as a unit of transmission, and in this case (FIG.3A), each subframe can be considered to be a slot.

For NR (5G) FIG. 3C shows NR TDD configurations, FIG. 3D showsNrTddConfig Definitions, and FIG. 3E shows NrTDDUIDIPattern Definitions.FIG. 3C shows an example of slot configurations for a 30 kHz spacing. Aslot is used by scheduling mechanisms as a unit of transmission of OFDMsymbols.

TDD Configuration Selection Procedure

The following message exchanges are defined between the CxM and a CBSDor DP. These messages are being defined in standards.

For a Request from a CBSD/DP to the CxM some messages are:

-   -   desiredTddConfig;    -   desiredNrTddConfig;    -   usedTddConfig;    -   usedNrTddConfig;    -   fallbackTddConfig; and    -   indoorCbsdOptOut.

For a response from a CxM to the CBSD, some messages are:

-   -   eutraTddConfig;    -   nrTddConfig;    -   coexMeasAssist; and    -   cbsdFrequencyGuidance.

In order to select a TDD configuration by a CBSD or DP (CBSD/DP), votingprocedures are utilized, and may be defined in standards. If LTE-TDD andNR-TDD CBSDs belonging to the same TDD Configuration Connected Set(TCCS) select different TDD Configurations, the CxM designate the use ofone of the mandatory TDD Configurations. In a TCCS containing onlyNR-TDD CBSDs, an NR-TDD Configuration not compatible with LTE-TDD may beused, provided that all NR-TDD CBSDs in the TCCS use the same orEquivalent TDD Configuration. The TCCS that the CxM constructs can bedifferent from the Channel Assignment Connected Sets. For example, theseConnected Sets can be different in the case where indoor CBSDs opt outof the TCCS.

In order to select a TDD configuration in a TCCS, the followingprocedures may be used. If all the CBSDs in the TDD ConfigurationConnected Set specify the same desired TDD Configuration including theSSF selection (the desired TDD Configuration may be outside of the setof mandatory TDD Configurations), then the desired TDD Configurationbecomes the TDD Configuration to be used in that TDD ConfigurationConnected Set. Otherwise, the fallback TDD configuration is be chosen bymajority voting among the fallback TDD Configurations specified by CBSDswithin the constructed baseline TDD Configuration Connected Set

An Indoor CBSD can opt out. The standards provide that the CxM shallrequest Indoor CBSDs to employ the mandatory TDD Configurations onlywhen harmful interference scenarios originated by the Indoor CBSDs arereported. Also, the CxM shall consider fallback TDD preferences ofIndoor CBSDs that have requested to opt out, if these CBSDs are going tobe mandated a TDD Configuration.

For a NR (5G) CBSD, the CBSD may specify the desired NR-TDDConfiguration including an SSF selection that is not compatible withLTE-TDD Configurations to the CxM. The standard provides that if all theCBSDs in a TCCS specify the same or Equivalent NR-TDD Configuration,then the CxM shall allow that NR-TDD Configuration to be used.

The TCCS is determined by the CxM. The CxM responds to the CBSD/DP,providing the TDD configuration to use, whether the CBSD/DP is LTE orNR. The CxM provides information to the CBSD as assistance informationfor coexistence measurements. The CxM provides CBSD frequency guidance;particularly, the CxM provides guidance on the frequency range(s) theCBRSA CxG CBSD is instructed to request and use going forward. Uponreceiving this information, the CBRSA CxG CBSD is expected to onlyrequest and hold spectrum grants that are within the receivedcbsdFrequencyGuidance. In a scenario in which the guidance last receivedfrom the SpectrumInquiryResponse->availableChannel object is in conflictwith the last received cbsdFrequencyGuidance, the CBSD should follow thelatter for determining the frequencies on which to request spectrumgrants.

Regardless of complexities, the CBRS band provides an opportunity tocreate new wireless networks, and there is a desire for utilizing andmaking maximum use of spectrum in the CBRS band while following therules pertaining the CBRS usage, including effectively responding todirections from the SAS.

PAL CBSDs and GAA CBSDs in Independent TCCS's

The standards may evolve to support PAL and GAA in independent TCCS'sfor TDD config selection. A PAL CBSD can join a GAA TCCS, if desired,and in that case, it is likely that the PAL CBSD(s) will select TDDconfig 2. However, there are use cases for enterprises where increasedUL capacity is required and choice of TDD config 1 may be desirable forthe GAA TCCS, although TDD config 2 is being used. In this case justchanging one TCCS to TDD config 1 will be problematic as there will betwo slots that can face interference (intra/inter/cross-link), which maybe harmful. For example, in the LTE (4G) TDD configuration (FIG. 3C) itcan be seen that in slot 3, TDD config 2 is downlink (D), and TDD config1 is uplink (U), which can create interference issues.

This interference issue may not exist at initial deployment and mayhappen based on subsequent deployment of PAL nodes. It may also varyfrom time to time dependent upon current network use and the number ofUEs operating at a particular time. This issue may indicate problems forindoor/outdoor deployments and CAT-A (1 watt)/CAT-B (50 watt)deployments for example. A mechanism is required to detect and mitigatethis issue in the field.

Use of Secondary TDD Configurations

The voting for TDD configuration identifies the ‘primary’ TDDconfiguration to be used by the CBSDs in the TCCS. Also, the CBSDs areallowed to use a compatible TDD configuration to the primary TDDconfiguration—specified as a ‘secondary’ TDD configuration. Thissecondary TDD configuration typically has two slots that have thepotential for UL/DL mismatches, which can cause interference issues, andtherefore if interference is observed using a secondary configuration,as long as no harmful interference is being caused.

Example 1: TDD config #2 allows for TDD config #1.

Example 2: TDD config #1 allows for TDD config #0 or TDD config #2.

If interference is observed and reported to the CSAS (CxM+SAS), the CSASwill require the infringing CBSDs to switch to a ‘primary’ TDDconfiguration. Therefore, a mechanism is required to detect interferenceand mitigate the interference in the deployment.

Varying Interference

Based on the amount of activity in the given network and neighboringnetwork(s), there will be varying interference experienced over time.Interference detection techniques are required for at least some of thefollowing reasons:

-   -   Reliably determining the sources of the interference when it        happens;    -   Detection is especially important during known peak hours;    -   Detection technique can be repeated during off peak hours to        detect interference, or absence of interference;    -   To detect issues with co-channel, inter-frequency, and        cross-link interference aspects; and    -   To detect issues in specific slots of operation.

Knowledge of the deployed network can be useful, for example knowledgeof whether the antennas employed are directional antennas oromni-directional antennas can be useful. It would also be useful todetect the network type, such as LTE, NR, or LTE & NR, used in campusdeployments and neighbor deployments. It would also be useful to detectwhether LTE-compatible TDD configurations or NR-specific TDDconfigurations are used.

SUMMARY

In order to reduce interference in an Enterprise Network (EN), a probedevice for measuring TDD interference in an Enterprise Network (EN) isdisclosed that measures TDD interference from neighboring networks.Generally, TDD interference is caused due to mismatched TDDconfigurations in an RF footprint, and may originate in external(neighboring) networks, or internal sources. A method is also disclosedfor determining the TDD configuration used by neighboring networks, andfor mitigating interference effects.

Various embodiments are disclosed. The probe device may be situated on acampus of an EN that has a plurality of BS/APs that utilize a first TDDconfiguration for wireless communications. The probe device is situatedin the EN campus in position for measuring TDD interference between aneighboring wireless network, which utilizes a second TDD configurationthat may conflict with the first TDD configuration.

The probe device includes a wireless receiver for receiving wirelesschannels; a communication link with the Enterprise Network; a frequencyscanning unit; data storage; and a TDD measurement unit for measuringTDD interference data from the neighboring network, and providing thedata to the Enterprise Network over the communication link. The TDDmeasurement unit may include an SIB Measurement unit for receivingbroadcast SIBs signals from neighboring networks, a UL SINR MeasurementUnit, a DL SINR Measurement Unit, and a UL RSSI Measurement Unit. Theprobe device may be positioned in a fixed location in an EnterpriseNetwork campus, and connected to an external power supply.

In a disclosed embodiment, the wireless receiver has circuitry forreceiving CBRS channels and the frequency scanning unit has circuitryfor scanning CBRS channels; in some embodiments, the wireless receiverhas circuitry for receiving signals in adjacent bands, such as mid-bandsignals and C-band signals. The probe device may be a CBSD that has abuilt-in UE, such as a CAT-A CBSD. The probe device may further includesoftware and circuitry for performing RF environment scanning, NetworkPerformance testing, and Radio Performance testing.

A method of detecting interference from a neighboring wireless networkusing a probe UE is disclosed that includes positioning the probe devicein the EN campus where it can receive signals from the neighboringnetwork, receiving signals from the neighboring network in the probedevice, and determining the TDD configuration utilized by theneighboring network. Determining the TDD configuration of theneighboring network may include receiving neighbor SIBs from theneighboring network in the probe device. Determining the TDDconfiguration of the neighboring network may also include measuringcommunication data in slots where TDD interference can occur betweendifferent TDD configurations. In some embodiments determining the TDDconfiguration of the neighboring network may comprise measuring the ULSINR of the probe device at the BS/AP (eNB/gNB), including calculatingcross-correlation between two slots and determining TDD interferenceresponsive to the cross-correlation. In some embodiments determining theTDD configuration of the neighboring network may comprise measuring DLSINR in the probe device, including observing the HARQ feedbackperformance. In some embodiments determining the TDD configuration ofthe neighboring network may comprise measuring the UL RSSI or RSRP ofthe probe device at the BS/AP, including comparing the RSSI or RSRPbetween two slots. DL RSRP (or RSRQ) measurements can be made at theprobe UE to determine if there is cross-link (UL transmission fromanother UE in the proximity impacting a DL slot at the probe UE)interference seen.

In some embodiments the enterprise wireless network operates on theCitizens Broadband Radio Service (CBRS band), the BS/APs in the RANcomprise CBRS Devices (CBSDs) that are located at a campus location andform part of an enterprise network. In alternative implementations,other network architectures and other technologies, such as mm-wave, orspectrum purchased/licensed from others, could be utilized.

BRIEF DESCRIPTION OF THE DRAWING

The disclosed method and apparatus, in accordance with one or morevarious embodiments, is described with reference to the followingfigures. The drawings are provided for purposes of illustration only andmerely depict examples of some embodiments of the disclosed method andapparatus. These drawings are provided to facilitate the reader'sunderstanding of the disclosed method and apparatus. They should not beconsidered to limit the breadth, scope, or applicability of the claimedinvention. It should be noted that for clarity and ease of illustrationthese drawings are not necessarily made to scale.

FIG. 1 is an illustration of a basic configuration for a communicationnetwork, such as a “4G LTE” (fourth generation Long-Term Evolution) or“5G NR” (fifth generation New Radio) network.

FIG. 2 is a block diagram of a wireless communication network in which aCBRS system is implemented.

FIG. 3A is a table that shows LTE TDD configurations.

FIG. 3B is a table that shows EutraTddConfigObject definitions for 4Gcommunication systems.

FIG. 3C is a table that shows NR TDD configurations and slotconfigurations for a 30-kHz spacing.

FIG. 3D is a table that shows NrTddConfig definitions.

FIG. 3E is a table that shows NrTDDUIDIPattern definitions.

FIG. 4 is a perspective illustration of a campus location of anEnterprise Network.

FIG. 5 is a cross-sectional view of a building on the campus location.

FIG. 6 is a flow chart showing an overview of operations to use a ProbeUE to detect and mitigate TDD interference from a neighboring network.

FIG. 7 is a block diagram of one embodiment of a Probe UE.

FIG. 8 is a diagram showing Probe UEs/CBSDs in a deployed CBRSEnterprise network, and CBSDs in a neighbor network.

FIG. 9 is a block diagram illustrating the CBRS spectrum and theadjoining spectrum including the mid-band spectrum at the lower end andthe C-band spectrum at the upper end.

FIG. 10 is a flow chart of operations to read a SIB from a neighbornetwork.

FIG. 11 is a diagram showing two widely-used TDD configurations in 4G,including UL/DL slots in TDD config 1 and TDD config 2.

FIG. 12 is a flow chart of operations to detect TDD interference usingUL-SINR measurements.

FIG. 13 is a flow chart of operations to detect TDD interference usingHARQ feedback to make DL-SINR measurements.

FIG. 14 is a flow chart of operations to detect TDD interference usingUL-RSSI measurements.

FIG. 15 is a block diagram of an implementation of Probe UEs in anEnterprise Network (EN), and a Cloud-Based Network Orchestration Module.

The figures are not intended to be exhaustive or to limit the claimedinvention to the precise form disclosed. It should be understood thatthe disclosed method and apparatus can be practiced with modificationand alteration, and that the invention should be limited only by theclaims and the equivalents thereof.

DETAILED DESCRIPTION

Communication networks and system components are described herein usingterminology and components common to 4G (LTE) communication systems,and/or 5G (NR) communication systems. However, the principles of thecommunication network and microslices described herein more widely applyto other communication systems, not only to 4G or 5G systems.

(1) Enterprise Network

An implementation of an enterprise wireless communication network (EN)at a campus location is described herein. The term “enterprise” is usedherein in its broadest sense to include any organization, such asbusinesses, research organizations, schools, colleges, hospitals,industry organizations, and any other organization, regardless ofwhether or not for profit. The term “campus” is used in its broadestsense to include any area in which the enterprise operates, such as thegrounds and/or buildings operated or managed by the enterprise, collegecampuses, research centers, industrial complexes, any business orindustrial site, and others.

An enterprise wireless communication network (EN) is a private network.Private networks are operated for use within a limited area by a limitedgroup of authorized users, whereas public networks generally cover alarger area and are open for use by anyone that subscribes to theservice by the network operator. One or more ENs can be created at alocation such as a warehouse, factory, research center or otherbuilding, and are usually operated by an organization for its own use.Other types of private networks may be operated by a private networkmanager for use by more than one organization. Although described in thecontext of an enterprise wireless communication network, the principlesdisclosed can also apply to any private wireless network.

An EN may comprise any appropriate wireless network technology that canconnect to UEs. For example, the LTE (4G) network shown in FIG. 1 and/orthe NR (5G) Network shown in FIG. 2 can be implemented in an EN. Inaddition, the EN may also be implemented as a CBRS network using, forexample, the LTE (4G) or NR (5G) technologies; particularly, in someembodiments the enterprise wireless network operates on the Citizen'sBroadband Radio Service (CBRS band), the BS/APs in the RAN comprise CBRSDevices (CBSDs) that are located at a campus location and form part ofan enterprise network. In alternative implementations, other networkarchitectures and other technologies, such as mm-wave, or spectrumpurchased/licensed from others, could be utilized.

(2) Communication Networks

Communication networks and system components may be described hereinusing terminology and components relating to 4G, 5G, and CBRS systemsand their approved (registered) interfaces including 4G (LTE) (IEEE802.16e), 5G NR 3GPP TS 38.300, E UTRA (3GPP TS 36.300) communicationsystems. For instance, the term “CBSD” is one implementation of a BaseStation/Access Point (BS/AP) and is used herein for descriptive purposesin the context of a CBRS system. The principles of the communicationnetwork described herein more widely apply to other communicationnetworks and systems, and particularly to any spectrum-controlledcommunication system and network. In some embodiments, the enterprisewireless communication network operates on the CBRS band, and the BS/APscomprise CBRS devices (CBSDs) that are located at a campus location.

(3) Functional Blocks and Communication Links

A functional block is a computing element that performs any activityrequired to implement a set of logical operations. The functional blockmay include a dedicated processing circuit that performs an intendedfunction, or it may be a software-implemented process across circuitsthat performs the intended function. In the current disclosure, theactivity required to implement a set of logical operations is performedfor the purpose of facilitating end to end communication (e.g., betweena UE and an external server). In the communication context, thefunctional block may be in the control plane or the user plane. Tomonitor a functional block, control information is exchanged between theblock and the orchestrator. For example, the orchestrator may make aquery, and the functional block may respond.

A communication link is a connection between two functional blocks thatprovides communication between the two functional blocks. Thecommunication link may include any appropriate connection type, such aswireless or wired, and utilize any suitable protocol. The link and/orprotocol may be secure or otherwise. A communication link may bemonitored at any point in the link, for example it may be monitored atits entry point and/or its exit point to provide performance data.

(4) Acronyms

Some of the acronyms used herein are as follows:

3GPP: 3^(rd) Generation Partnership Project

ANR: Automatic Neighbor Relation

BS/AP: Base Station/Access Point

CA: Carrier Aggregation

CAT-A: Category A CBSD

CAT-B: Category B CBSD

CBRS: Citizen's Broadband Radio Service

CBRSA: CBRS Alliance

CBRS-NID: CBRS Network ID

CBSD: CBRS devices

CCG: Common Channel Group

CPE: Consumer Premises Equipment

CQI/SRS/DMRS information

CSAS: CxM and SAS

CSG: Closed Subscriber Group (GSM/LTE concept re-used by CBRSA asCBRS-NID)

CxG: Coexistence Group

CxM: Coexistence Manager

DL SINR

DP: Domain Proxy

ECGI: E-UTRAN Cell Global Identifier, composed of HNI+Macro eNB ID+CellID

EN: Enterprise Network

eNB GAA

E-UTRA

GAA: General Authorized Access

HARQ: Hybrid Automatic Repeat request

HO: Handover

ICG: Interference Coordination Group

LTE: Long Term Evolution (4G)

NR: New Radio (5G)

OFDM: Orthogonal Frequency Division Multiplexing

PAL: Priority Access License

PPA: PAL Protection Area

PCI: Physical Cell Identifiers

PDN: Packet Data Network

PDSCH: Physical Downlink Shared Channel

PER: Packet Error Rate

QCI: QoS Class Index

QoS: Quality of Service

RAN: Radio Access Network

RAT: Radio Access Technology

RF: Radio Frequency

RRC: Radio Resource Control

RSRP: Reference Signal Received Power (a measurement of the receivedpower level in a wireless network)

RSRQ: Reference Signal Received Quality

RSSI: Received Signal Strength Indication

Rx: Receiver

SAS: Spectrum Access System

SCS: Sub-Carrier Spacing

SF: Sub-Frame (in LTE, a slot is the same a subframe)

SIB: System Information Block. (System information is broadcast using aMaster Information Block (MIB) and a series of SIBs.)

SINR: Signal to Interference-plus-Noise Ratio

SME: Spectrum Management Entity

SON: Self Organizing Network

SRG: Spectrum Re-use Group

SSF: Special Sub-Frame

TCCS: TDD Configuration Connected Set

TCP: Transmission Control Protocol

TDD: Time Division Duplex

Tx: Transmitter

UDP: User Diagram Protocol

UE: User Equipment

UL: Uplink

UL RSSI: Uplink RSSI

(5) UEs, BS/APs, RAN, Core Network

As used herein, the term “UE”, or “devices”, or “UE devices” refers to awide range of user_devices having wireless connectivity, such as acellular mobile phone, an Internet of Things (IOT) device, virtualreality goggles, robotic devices, autonomous driving machines, smartbarcode scanners, and communications equipment including for examplecell phones, desktop computers, laptop computers, tablets, and othertypes of personal communications devices. In some cases, the UEs may bemobile; in other cases, they may be installed or placed at a fixedposition within a campus location. In other examples, the UEs mayinclude factory sensors installed at fixed locations from which they canremotely monitor equipment such as an assembly line or a robotic arm'smovement. Examples of services that can be provided to UEs by a wirelessnetwork include:

-   -   voice calls;    -   web browsing;    -   downloads of document or other information;    -   video (e.g., YouTube);    -   social media (e.g., Facebook, Twitter); and    -   video security cameras, sensors, and many others.

The UEs connect wirelessly over radio communication links to a RadioAccess Network (RAN) that typically includes multiple basestation/access points (BS/APs) that include antennas, amplifiers, andother electrical and control units for communicating with the UEs.Typically, the radio communication links operate using a Radio ResourceControl (RRC) protocol, which is managed by circuitry in the BS/APs.

The term ‘BS/AP” is used broadly herein to include base stations andaccess points, including at least an evolved NodeB (eNB) of an LTEnetwork or gNodeB of a 5G network, a cellular base station (BS), aCitizens Broadband Radio Service Device (CBSD) (which may be an LTE or5G device), a Wi-Fi access node, a Local Area Network (LAN) accesspoint, a Wide Area Network (WAN) access point, and should also beunderstood to include other network receiving hubs and circuitry thatprovide access to a network of a plurality of wireless transceiverswithin range of the BS/AP. Typically, the BS/APs are used as transceiverhubs, whereas the UEs are used for point-to-point communication and arenot used as hubs. Therefore, the BS/APs transmit at a relatively higherpower than the UEs.

A Core Network provides a number of functions and services, including aninterface between the RAN and other networks. In one important function,the Core Network provides the UEs in the RAN with access to otherdevices and services either within its network, or on other networkssuch as the External PDNs. Particularly, in cellular networks and inprivate networks, the UEs wirelessly connect with BS/APs in the RAN, andthe RAN is coupled to the Core Network. Therefore, the RAN and the CoreNetwork provide a system that allows information to flow between a UE inthe cellular or private network and other networks.

In addition to providing access to remote networks and allowinginformation to flow between the cellular network and the external PDNs,the Core Network may include RAN Control Units that manage the wirelessnetwork and provide control of the air interface between the BS/AP andthe UEs. The Core Network may also coordinate the BS/APs to minimizeinterference within the network.

(6) CBRS Networks

A Citizen's Broadband Radio Service (CBRS) system is a wireless,spread-spectrum communication system that includes a plurality ofwireless channels, and is subject to certain operational rules. A CBRSnetwork utilizes the CBRS radio band of 3550-3700 MHz, nominally dividedinto fifteen channels of 10 MHz each. Particularly, the US FederalGovernment recently approved use of the CBRS band of the frequencyspectrum and finalized rules (Rule 96) that allow general access to theCBRS band. The CBRS rules set forth detailed requirements for thedevices that operate in a CBRS network and how they communicate. BothLTE networks and 5G networks can be implemented in CBRS systems. Basestations (BS/APs) within a CBRS network are termed “CBSDs”, and UEs aretermed End User Devices (EUDs). All the CBSDs are connected to anoperator Core Network by any appropriate communication means, such aswire, fiber optic, wireless radio and/or a PDN, which includescomponents such as an OAM Server, a SON assist unit, a Domain Proxy, anAutomatic Configuration Server (ACS), a Location Database, and otherdatabases, all of which are connected to each other within the operatorCore Network by any appropriate means. The operator Core Network isconnected to an SAS, which is connected to a Spectrum Database thatincludes data regarding the spectrum that it is managing; collectively,the SAS and the Spectrum Database are referred to as a SpectrumManagement Entity (SME).

(7) RF Environment, Campus Location

The design of a wireless network deployment, and the allocation ofresources in a deployed RAN, is greatly dependent upon the RFenvironment at the campus location where the RAN is deployed. At any RANdeployment, the RF environment can vary due to a variety of causes; forexample, physical obstacles like buildings affect the RF environment,also the relative positioning of the transmitters and UEs, interference,campus layout, features, and building construction: walls, materials,carpeted/non-carpeted all can affect the RF environment and may varywidely between locations. In other words, the RF environment can varygreatly within a RAN, and accordingly each BS/AP may see a differentpath loss.

Following are examples of a campus location and a building in which aRAN is deployed, all of which contribute to the RF environment.Particularly, FIG. 3 is a perspective illustration of a campus location400 that has wireless coverage and FIG. 5 is a cross-sectional view of abuilding 500 on the campus location 400.

FIG. 4 is a perspective illustration of a campus location 400 in which aplurality of BS/APs including at least a first BS/AP 410 a, a secondBS/AP 410 b (collectively 410) of an Enterprise Network (EN) (sometimesthe “deployed network”) are installed to provide wireless coverage to aplurality of mobile users such as a first user 420 a a second user 420b, and a third user 420 c (referred to collectively as 420). Each mobileuser 420 may be carrying one or more UEs such as a mobile phone, laptopcomputer, or some other device that can be connected to the EN.

The campus location 400 defines a boundary perimeter 402, and the BS/APs410 are deployed within the boundary 402. The positions andconfiguration of the BS/APs 410 deployed within the campus location 400are selected to provide wireless coverage to the plurality of users 420for the EN. The BS/APs 410 may be installed indoors and outdoors, andmay comprise any type of BS/AP. The BS/APs 410 generally providewireless coverage substantially throughout the campus location 400,indoor and outdoor, with coverage usually extending to surrounding areasat least to some extent. In one embodiment the BS/APs 410 comprise CBSDsand the EN includes a CBRS network. In some embodiments some of theBS/APs 410, particularly the BS/APs installed indoors, have a UE builtinto them. These built-in UEs can be used for making measurements thatcan be used to determine the MN footprint information, as describedherein.

Outside the campus location 400, there may be a number of neighbornetworks, including a first neighbor network 440 that include aplurality of BS/APs 442 and a second neighbor network 450 that includesa plurality of BS/APs 452. The wireless communication signals from theseneighbor networks can interfere with wireless communication in the EN.Particularly, the wireless BS/APs and UEs in the neighboring networksmay be operating using a different TDD configuration than the EnterpriseNetwork, which can cause TDD interference. Generally, TDD interferenceis caused due to mismatched TDD configurations in an RF footprint, andmay originate in external (neighboring) networks, or internal sources.

In FIG. 4 , to detect TDD interference as will be described in detail, afirst probe UE 700 a (see FIG. 7 ) is positioned on the campus 400,close to the boundary 402, and near to the first neighbor network 440.Similarly, a second probe UE 700 b (see FIG. 7 ) is positioned on thecampus 400, close to the boundary 402, and near to the second neighbornetwork 450 to detect TDD interference from the second neighbor network450.

FIG. 5 is a cross-sectional view of a building 500 on the campuslocation 400 in which a plurality of BS/APs of the RAN are installed ondifferent floors. In this example, a first BS/AP 510 a is installed onthe sixth floor 506, a second BS/AP 510 b is installed on the fourthfloor 504, a third BS/AP 510 c is installed on the first floor 501, anda fourth BS/AP 510 d is installed in the basement 509. Buildingconstruction (walls, materials, carpeted/non-carpeted) can vary widelybetween locations, and all can affect the RF environment. In someembodiments, the indoor BS/APs 510 have a UE built into them, which canbe used for making measurements.

(8) Overview: Interference Detection and Mitigation

FIG. 6 is a flow chart showing an overview of operations, starting at600, to use a probe UE in a CBRS network to detect and mitigate TDDinterference from a neighboring network. First, a probe UE is obtained.(STEP 610). A probe UE is described in more detail with reference toFIG. 7 . The probe UE is then positioned (deployed) on the EnterpriseCampus (STEP 620), which is described in more detail with reference toFIGS. 4 and 6 .

Once deployed on the Enterprise Campus, the Probe UE can measure TDDinterference data (STEP 630). Any of a number of methods may be utilizedby the Probe UE for detecting interference including:

-   -   Reading neighbor CBSD SIBs (System Information Blocks), using        the neighbor SIBS that are broadcast freely, providing a        broadcast message that any receiving device within range can        read.    -   Detection using UL SINR (Uplink Signal-to-Interference plus        Noise Ratio).    -   Detection using DL SINR (Downlink SINR).    -   Detection using a signal strength measure such as UL RSSI        (Received Signal Strength Indicator) or RSRP (Reference Signal        Received Power).

Information from probe UEs in an EN campus is then reported (STEP 640)to the Enterprise Network, and collected at a centralized location, suchas the orchestrator (see FIG. 15 ). At the centralized location, the TDDinterference data can be analyzed and the TDD interference source can beidentified, or at least a reasonable determination can be made. (STEP650).

Responsive to the TDD interference determined from the previousoperations, steps can be taken to mitigate or resolve the TDDinterference problem. (STEP 660) Mitigation options are disclosed formitigating interference after detecting potential interference. Onemitigation option is to switch the TDD config, perform detectionoperations, and observe the results. Resolution actions, for determininghow to switch the TDD configuration if a potential problem is detected,are also disclosed.

The same principles of detecting TDD interference can also be applied todetect TDD interference within the Enterprise Network or on theEnterprise campus itself. For example the same principles andmeasurements performed can be used to detect the TDD configurationacross channels/cells that are deployed within the same network; forexample it can be used to detect a security camera system that requiresUL centric TDD slot configuration while Internet traffic requires a DLcentric configuration. The deployed network can be partitioned tosupport different TDD configurations based on the use cases/devicesconnected to the individual BTS-CBSDs. The footprint and interferenceimpact can be measured to optimize a given deployment as well.

(9) Mitigation and Resolution

If interference has been detected, following are some options formitigation and resolution:

-   -   Check performance after restricting specific UEs to        non-conflicting UL slots to see if the performance improves.        This can be empirical detection, and may operate continuously    -   Deploy a probe on campus to check infringing networks.    -   Identify the issue and talk to SAS vendors to see if the problem        can be resolved through other means including realignment of        channel assignments. In this option, a potential TDD config        switch can be delayed until it is determined that the TDD really        needs to be changed. This approach will allocate channels to        CBSDs that are close to (nearby) the interfering entities, so        that the channel assignments are farther apart.    -   Limit use of interfering channels to locations farther inside        the building.    -   Switch to another TDD config if nothing else can be done to        resolve the issue.

(10) How to Switch the TDD Config after a Problem is Detected

The TDD config can be switched as follows:

1. If TDD Config is ‘0’ or ‘1’, the system may switch to TDD Config 2.

2. Switching the TDD config will require a round of negotiations withthe CSAS.

3. Switching to TDD Config 2 may result in a capacity drop and mayrequire the network to be re-planned.

One proactive alternative is to plan the network based on TDD Config 2,and opportunistically use TDD Config 1, such as for deployments that maybe at potential risk of encountering such interference. If needed thesystem can then be switched to TDD Config 2 without re-planning thenetwork.

After mitigation/resolution (STEP 660), operations to detect andmitigate TDD interference from a neighboring network in FIG. 6 arecomplete (STEP 670).

(11) Probe UEs

FIG. 7 is a block diagram of one embodiment of a Probe UE 700.Generally, a Probe UE is a device that can receive wireless signal in aplurality of bands, store signal qualities, and send them to a corenetwork. A Probe UE may be a conventional UE such a mobile phone,tablet, or laptop, and it may be enhanced with other capabilities, suchas the ability to connect with a modem and get communication informationand statistics from it. Usually, a conventional mobile device includesall necessary or useful hardware; e.g., hardware to measure all CBRSchannels and adjoining channels, and report to the core network. The UEcan be programmed to perform operations described herein. Generally, aprobe UE will be connected to a continuous power source, so battery lifeis not an issue, so some mobile UE operations may be deferred to theprobe UEs. Also, a Probe UE may also be in the form of any CustomerPremises Equipment (CPE), which includes any telecommunications andinformation technology equipment on the campus, such as telephoneheadsets and modems that can perform the Probe UE functions.

In the block diagram of FIG. 7 , the Probe UE 700 includes a wirelessreceiver 710, a communication link 712 with the RAN/Core Network(wireless or wired), a processor 714, data storage 716 and a battery(power source) 718 that may be connected to an external power supply720. The Probe UE 700 has circuitry and software to perform operationsand measure signal qualities, such as a frequency scanning unit 730, aunit 740 to read the SIBs of neighbors (may be used to detect the TDDconfigurations in use in the neighbor networks, as described withreference to FIG. 10 ), and signal strength measuring units such as a ULSINR measurement unit 750 (see operations in FIG. 12 ), a DL SINRMeasurement Unit 760 (see operations in FIG. 13 ), and a UL RSSIMeasurement Unit 770 (see operations in FIG. 14 ). A plurality ofsoftware packages 780 may be installed in the Probe UE 700, which mayimplement procedures and probe UE functions, for example RF EnvironmentScanning, Network Performance Monitoring and Tests, Radio Performance,and a Sanity Suite, which are described elsewhere in this application.

In some embodiments, the wireless receiver 710 may include circuitry tomeasure channels adjacent to the CBRS band. FIG. 9 is a block diagramillustrating the CBRS spectrum 920 and the adjoining spectrum includingthe mid-band spectrum 910 at the lower end and the C-band spectrum 930at the upper end. The fifteen channels within the CBRS spectrum areshown, and in a CBRS implementation, the probe UE has the hardware andsoftware to receive signals in these fifteen channels. In someembodiments the probe UE 700 can also detect interference signals in theneighboring portion of the mid-band spectrum 910 and/or the C-bandspectrum 930 adjacent to the CBRS channels, where interference mayoccur. Particularly, these Probe UEs have the hardware and software toscan the adjacent bands, and report it to the network.

The probe UE 700 could be a dedicated UE device, or could be part of aCBSD that has UE capabilities built-in. Particularly, in a CBRSembodiment, Probe UEs (Probe Nodes) used for detecting neighborinformation may include:

-   -   For CAT-A CBSD: use the built-in UE (the UE built into the CBSD)        to perform a periodic check of the other CBRS channels to see if        SIB-1 broadcasts indicate the use of TDD Config 2;    -   For CAT-B CBSD: Built in UEs are typically not included with        CAT-B APs;    -   Specific UEs may be deployed at a particular location on the        enterprise campus as probe UEs.

(12) Deploying and Positioning Probe UEs

FIG. 8 is a diagram showing CBSDs 822, 824, 826, 828 in a deployedEnterprise network 820, and also showing CBSDs 812, 814 in a neighbornetwork 810. The CBSDs in each network can be CAT-A, CAT-B or any othertype of CBSD that may become implemented in CBRS networks. In theexample of FIG. 8 , the neighbor network 810 is shown including a firstCBSD 812 that is a CAT-A type, and second CBSD 814 that is a CAT-B type.In any particular embodiment there may be many CBSDs of both types. Thedeployed network 820 includes CBSDs 822,824 that have probe UEs, whichare described herein.

Referring briefly to FIG. 4 , the first probe UE 700 a is positionednear to the first neighbor network 440 to detect TDD interference, and asecond probe UE 700 b (see FIG. 7 ) is near to the second neighbornetwork 450 to detect TDD interference from the second neighbor network450. In the diagram of FIG. 8 , the CBSDs with probe UEs are positionedproximate to the neighbor network 810; particularly in FIG. 8 , theCBSDs 822, 824 with probe UEs are positioned proximate to the neighbornetwork 810.

An outer layer 830 may be defined in the deployed network 820, adjacentto the neighbor network 810, that defines an area subject tointerference from the neighbor network 810.

In FIG. 8 , a probe UE 850 is illustrated situated in a position whereit can receive signals from both the neighbor network 810 and thedeployed network 820. Generally, a probe UE 850 is a wireless devicepositioned at a fixed, strategic location in, or proximate to, theenterprise location. The position may be between the two networks, or inan area where the signals from each network overlap to at least someextent. Typically, a probe UE will be positioned near or within theboundary of the enterprise location, where a mobile UE expects somelevel of service. Generally, it is not useful to place a probe UE withinthe neighboring network location because wireless coverage in theneighboring network is not of interest to the Enterprise Network.

The deployed network 820 may also include additional CBSDs in the insidelayer 840, positioned farther from the neighbor network 810 that do notinclude probe UEs. In FIG. 8 these CBSDs in the inside layer 840 includea CBSD 826 (CAT-A) and a CBSD 828 (CAT-B), in other embodiments theremay be many CBSDs of both types.

The Enterprise Network campus may be considered as defining outer layersin which UEs are subject to interference from a neighboring network andan inner (inside) layer substantially isolated from interference fromthe neighboring network. In an inside layer, all CBRS bands may beusable, and can be assigned to the BS/APs within those inside layers. Inoutside layers, in order to provide best service, CBRS bands can belimited to those that don't have much interference from neighboringnetworks.

(13) TDD Conflict Detection

As discussed above, the TDD configuration for a deployment is selectedby the CBSDs or some other mechanism within the deployment. Anyparticular TDD configuration selected for CBSD operation can be impactedby interference, for example interference may be caused by:

-   -   Other CBSDs deployed in the CBRS spectrum;    -   High power CBSD systems: for some environments: the FCC has        approved higher-powered (75 dBm urban/77 dBm rural) operation        relative to the CBRS channels (30 dBm CAT-A/47 dBm CAT-B); and    -   Interference from the adjoining mid-band spectrum (e.g., 2.45 to        3.45 GHz) or the adjoining C-band spectrum (e.g., 3.7 to 3.98        GHz).

(14) Detection by Reading Neighbor CBSD SIBs

CBSDs broadcast SIBs that include information useful for UEs that wantto connect to the network, and other information. The broadcastinformation includes the TDD configuration currently being used by theCBSD (and the network to which it is connected). Probe UEs can be usedto report information on neighbors deployed on the CBRS channels.

FIG. 10 is a flow chart of operations, starting at STEP 1000, to read aSIB from a neighbor broadcast. As discussed above, a Probe UE may bedeployed in a position in the Enterprise Campus where it can receivesignals from one or more neighboring networks, and may be able toreceive a broadcast (STEP 1010) from a CBSD in a neighboring network. Ifit can receive a broadcast, then it reads the SIB (STEP 1020),determines the TDD config used by the neighbor CBSD (STEP 1030), andthen reports the TDD config (STEP 1040) to the centralized location,such as an orchestrator, that uses this information to help analyze anddetermine TDD interference. This information may be used to mitigate orresolve any TDD interference determined.

It may be noted that interference will likely be sensed more easily(i.e., more detectable) on the UL side. Also, measurements of signalstrength of neighbor CBSDs may be recorded and reported.

(15) Detection Using UL and DL (FIG. 11)

FIG. 11 is a diagram showing UL/DL configurations including UL/DL config1 (shown at 1110) and UL/DL config 2 (shown at 1120). These twoconfigurations are examples of widely-used TDD configs. In slot 3 (shownat 1130) and slot 8 (shown at 1140), config 1 has a scheduled uplink,while config 2 has a scheduled downlink, which creates a conflict ifboth configs are operating at the same time and visible to CBSDs. So, ifthe Enterprise Network is using UL/DL config 1 and if a neighboringnetwork is using UL/DL config 2, then Enterprise Network CBSDs withinthe range of the neighboring network can experience a low UL SINR in SF3(subframe 3) and SF8.

Calculation steps are described, which may be performed in any suitableprocessing system, such as in the Probe UE/BSAP, in the core network, orin an orchestrator.

It may be noted that TDD detection operations may be repeated across theset of allowed channels to determine the best channel(s) to support aBTS-CBSD, so that the required TDD configuration (DL centric or ULcentric) can be supported. For example, in a CBRS deployment, thedetection operations may be repeated across all 15 available channels.Note that these measurements can be performed from either or both of theUE/CPE-CBSDs and the BTS-CBSDs in the Enterprise Network.

(16) Detection of TDD Conflict Interference by Using UL SINR

FIG. 12 is a flow chart of operations to detect TDD interference usingUL-SINR measurements. Beginning at 1200, one embodiment of the method toidentify TDD conflict interference detects the UL SINR in accordancewith the following:

A BS/AP receives a UL signal (STEP 1210) and measures the UL SINR (STEP1220) in each SF (slot) in every radio frame. The UL SINR is typicallymeasured in a BS/AP, which may be a CAT-A BS/AP that has a built-in UE.Although SINR is typically measured at the BS/AP, and in someembodiments can be measured in a Probe UE.

Next, the measured SINR per Resource Block (RB) is averaged over aperiod. (STEP 1230).

Next, a determination is made as to whether the UL SINR in slots wherethere may be a conflict is lower than other non-conflict slots (STEP1240). Particularly, if there is a UL/DL conflict between the EnterpriseNetwork and a neighboring network, then the UL SINR for SF3 and SF8should be lower, on average, over the measurement period than otherslots. For a fixed UE and RB, the UL SINR cross correlation of SF3 andSF8 would be higher compared to the cross correlation of another slot(such as SF2) and SF3. Therefore, the existence of a conflict can beshown by calculating the cross correlation of SF3 vs SF8, and also thecross correlation of SF2 vs SF3, (STEP 1250) and comparing them (STEP1260).

If from the cross-correlation comparison (STEP 1260) the UL SINR issufficiently lower, then using these predictors, the Enterprise Networkmay be able to identify the TDD interference (STEP 1270) and determinethe presence of a neighboring enterprise that is using a different UL/DLconfiguration, and creating interference. Operation to detect TDDinterference using UL SINR then ends (STEP 1280).

The UL SINR TDD detection operations may be repeated for each frameacross the set of allowed or available channels.

(17) Detection Using DL SINR

FIG. 13 is a flow chart of operations to detect TDD interference usingHARQ feedback to make DL-SINR measurements. Beginning at 1300, oneembodiment of the method to identify TDD conflict interference operatesin accordance with the following:

Since a BS/AP (or UE) cannot detect DL SINR directly, it can use HARQfeedback (which measures repeat requests) to determine the DL SINR forSF3 and SF8 and the other slots. A BS/AP receives DL signals (STEP 1310)and observes HARQ feedback (STEP 1320) in each SF (slot) in every radioframe. The DL SINR is typically measured in a BS/AP, which may be aCAT-A BS/AP that has a built-in UE. Although HARQ feedback is typicallymeasured at the BS/AP, and in some embodiments can be measured in aProbe UE.

Next, the HARQ feedback performance per Resource Block (RB) is averagedover a period. (STEP 1330).

Next, a determination is made as to whether the DL SINR in slots wherethere may be a conflict is lower than other non-conflict slots (STEP1340). Particularly, if there is a UL/DL conflict between the EnterpriseNetwork and a neighboring network, then the DL SINR for SF3 and SF8should be lower, on average, over the measurement period than other,non-conflict slots. For a fixed UE and RB, the DL SINR cross correlationof SF3 and SF8 would be higher compared to the cross correlation ofanother non-conflict slot (such as SF2) and SF3. Therefore, theexistence of a conflict can be shown by calculating the crosscorrelation of SF3 vs SF8, and also the cross correlation of SF2 vs SF3,(STEP 1350) and comparing the cross-correlations (STEP 1360).

If from the cross-correlation comparison (STEP 1360) the DL SINR issufficiently lower, then using these predictors, the Enterprise Networkmay be able to identify the TDD interference (STEP 1370) and determinethe presence of a neighboring enterprise that is using a different UL/DLconfiguration, and creating interference. Operation to detect TDDinterference using DL SINR then ends (STEP 1380).

Again, as in UL SINR, HARQ feedback performance for each SF is averagedover a period. Like UL, DL SINR metrics will be used to findcross-correlation across SF's.

The DL SINR TDD detection operations may be repeated for each frameacross the set of allowed or available channels.

(18) Detect Using UL RSSI

A DL slot that is interfering with a UL slot can also be detected usingthe RSSI in the UL communications. FIG. 14 is a flow chart of operationsto detect TDD interference using UL-RSSI measurements. Beginning at1400, following is the method for detecting TDD interference usingUL-RSSI:

Select a lean (low-usage) time period (e.g., midnight) to measure RSSI(STEP 1410). “Low usage” in this context means that there are fewer ULtransmissions in the neighbor enterprise at that time.

Measure the UL RSSI across entire CBRS bandwidth during the selectedmeasurement period (STEP 1420), in the times corresponding to targetslots SF2, SF3, SF7 and SF8. In order to avoid measuring RSSI from UEsin the Enterprise Network in the target slots, the Enterprise Networkensures that UEs in the Enterprise Network are not transmitting on thetarget slots during the measurement period (STEP 1430). In oneembodiment the Enterprise network can schedule a ghost UE (not tied to aspecific UE) across entire bandwidth, which has the effect of preventingother UEs from transmitting during that period. Once it is “scheduled”that no UEs are transmitting on the target slots during the selectedmeasurement period, the RSSI can be measured on that channel, whichgives a raw RSSI. Scheduling is generally performed in the core network,and managed by the orchestrator. For example, the orchestrator canselect and manage the measurement period, and analyze the results.

The RSSI measurements can now be reported, e.g., to the orchestrator,(STEP 1440) where they can be analyzed (STEP 1450). As part of theanalysis, the RSSI values can be calculated for SF2, SF3, SF7, and SF8,and compared between slots SF2 and SF3, and between slots SF7 and SF8.(STEP 1460).

In order to determine if the measured RSSI in slots 3 and 8 is due to ULtransmissions in the neighbor network and not due to DL transmission,the RSSI measurements are analyzed. If UL transmissions are not present,then there should not be much additional RSSI. However, if DLtransmissions are present, then DL RSREs (downlink resource elements)are present, which would add a proportional value to the RSSI. The RSSIcomparison is tested (STEP 1470), and if this proportion is same betweenSF2 and SF3 and between SF7 and SF8, then it is likely that config 1 isbeing used (STEP 1480), because SF2 and SF7 are uplink slots in bothconfig 1 and config 2. However, if the RSSI is higher on SF3 and SF8than in SF2 and SF7, then the probability of a neighbor with UL config 2is higher (STEP 1480).

The above RSSI process can be repeated at a busy hour, which can providea comparison between a low-usage time and the busy hour, for analysis.

Operations to measure TDD interference using UL RSSI are now complete(STEP 1490).

The UL RSSI TDD detection operations may be repeated for each frameacross the set of allowed or available channels.

(19) Config Registration and Detection System

In a config registration and detection system (not shown), UEs can beopportunistically used to provide information regarding configurationsbeing used by neighbors. In order to provide information for this configregistration and detection system, each enterprise first registers itsCBSD IDs and their respective geo-locations together with their CBRS IDsin a registry that may be provided by a third-party service “X”. Also,each CBRS deployment registers the UL/DL config for a geo-location in asecond registry. The first and second registries may be colocated in thesame computer system, and may be maintained by the same third-partyservice X. In one embodiment, a CxM as defined in the CBRS standards canprovide the third-party service X.

One algorithm to utilize this registered information to detectinterference is as follows:

1. Choose one or more border UEs (i.e., UEs that are entering thedeployed network) to do ECGI (EUTRA cell global identity) measurements.Advantageously, a UE entering the system will have better sensitivity toneighbor site signals and have a higher likelihood of decoding the SIBsfrom them. The likelihood of successfully scanning the neighbor networkwill be better than with a REM (Radio Environment Measurement) scan.

2. Among the 20 MHz, 15 MHz, 10 MHz, 5 MHz rasters, choose one using arandom function outside the currently granted bandwidth, and scan thefrequency for any PCIs present on it.

3. For all the PCIs reported on the frequency, choose one PCI using auniform random function.

4. For a chosen PCI, the BS/AP will ask the UE to report the ECGI of thecell.

5. Once the ECGI is received, the BS/AP queries service X for the CBRSID and geolocation.

6. Service X can find the geo-location from the BS/AP ID and get theUL/DL config from geo-location.

7. Service X can report the UL/DL config along with CBRS id of theneighbor.

8. Over a period, different UEs entering the system from differentdirections will report different PCIs for different frequency. Assumingthe environment has slow rate of change and mostly static, the neighborenvironment can be better estimated and the rate of usage for each UL/DLconfig can be obtained along with the signal power.

As an alternative to a BS/AP, a probe UE can also be utilized in thisalgorithm.

(20) Detecting Interference Using the PER (Packet Error Rate) inSpecific Slots

One method of detecting interference using PER is as follows:

1. For select UEs, schedule the UL grants on slots that are likely toface interference from a neighboring CBSD operation:

-   -   The interference itself may stem from DL Tx from CBSD or due to        crosslink interference due to a nearby UE;    -   These interferences will also happen only when there is DL/UL        transmission that coincides with the PER detection is performed        on specific slots.

2. The tests are performed during known peak times and repeated withmultiple UEs and over several periods of time.

3. If there is consistent PER detected in e.g., the slots SF3 and SF8(over adjoining slots), then this indicative of a potential conflict inthe TDD configurations used in the deployed network and the neighbornetwork.

4. Check for PER measurements (at L2/L1) to see if there is a detectableincrease relative to UE CQI/SRS/DMRS information.

(21) (ECGI,CSG)->CBSD ID's->SAS Enquiry for TDD Config

Currently, the CBSD-to-SAS interface provides information on the channelavailability for a group of CBSDs as part of the ICG-based spectruminquiry. The SAS also provides the channel quality associated with eachCBSD for the available channels (it receives reported measurements andcreates an environmental “map”, that predicts the channel quality),based upon reported measurements. The SAS is also being integrated withthe CxM functionality to support TDD configuration selection throughmajority voting amongst the CBSDs that are part of TCCS. The CBSDs maybe allowed to use their ‘Secondary TDD configuration’ as long as it doesnot cause interference to the neighbors who are using the ‘Primary TDDconfiguration’.

The CSAS (CxM+SAS) interface to the CBSD can also be enhanced to providethe TDD configuration used by the neighboring CBSDs so that a potentialsource of interference can be detected. The CSAS interface can be usedto provide this. The EN can also provide TDD info to the CSAS.

(22) Probe UE Capabilities and Procedures (23) Overview of a UE ofInterest to Use as a Probe UE

The UE of interest will be a fixed device at a strategic location in anenterprise location. The UE may have installed software programs thatprovide a variety of functions such as supplying information to supportthe network and improving network operation. The UE may be able to doany of the following:

-   -   Scan the environment (over time) for any change;    -   Do sanity test (defined below) in the environment;    -   Do a performance test (defined below) in the environment; and    -   Perform a radio performance test (defined below).

(24) Scanning Environment Tests

Any of these tests can be implemented in a software package that can runon a Probe UE, to build the picture of the network RF environment, usingdata from the probe UE's perspective:

1. Check if there is any new neighboring enterprise (CBSD) that isradiating and report the radiated RSRP. (Reference Signal ReceivedPower: a measurement of the received power level in a wireless network.)

2. Monitor SON power changes over time and determine the differencebetween the expected coverage and the achieved coverage. Note if the UEobserves a significant difference between the expected coverage andachieved coverage. Raise an alarm if the SON algorithm change hasresulted in HO (HandOver) failures or coverage holes.

3. Monitor the neighboring network(s) over a period of time anddetermine whether the RSRP of neighbors has changed, and if so, raise analarm. (This could be items in the warehouse sort of environment). Thisalarm can be used, for example, as a trigger to switch on additionalBS/APs or perform a new power allocation.

4. Offload ANR (Automatic Neighbor Relation) activity from other UEs(non-probe UEs) to the probe UE. If there is an environment change scanthe environment and populate the ANR table in the BS/AP (useful if noother service is doing it).

(25) Network Performance Test Suite

A Network Performance test suite can be implemented in a softwarepackage that can run on the UE, coordinated between cloud application(s)and the UE. The network performance test suite monitors networkperformance, and has the purpose of providing useful information to theEnterprise Network that may lead to improved performance.

1) The performance suite might include test running ping, UL load, DLload, UL/DL load, UDP and TCP traffic for different QCI's and reportingthe results and context to the enterprise management's cloud service.

2) During setup or reconfiguration, a network goes through a churn as itgets orchestrated, during which the network behaves differently, andperformance may be affected until the network stabilizes. There is alsothe backhaul which can behave differently with time of day. Theseproblems can be detected when there are enough UEs and loads on thesystem. Otherwise, it will be detected when the system gets loaded.

To avoid surprises, an enterprise can run these performance tests, athigher load, at different lean hour points in the day to collectrelevant information from different load levels.

3) A machine learning service can detect a potential problem using thedata collected from the probe UEs. However, the theory can be tested byrunning specific tests using a UE of interest.

(26) Radio Performance Test Suite

1. The UE of interest can be used to perform radio/scheduleroptimization:

a) Schedule each PRB on the UL, and monitor the UL performance and checkthe SINR and the CRC errors (at the BS/AP), to estimate the performanceof the PRBs.

b) Schedule each PRB on the DL, and monitor the DL performance and checkthe HARQ (Hybrid Automatic Repeat Request) feedback at the BS/AP or UE.

c) Use (a) and (b) for PRB ranking in the UL and DL.

We can seed the initial set of PRBs and transmission schemes for the UEsconsidered close to the UE of interest (by triangulation or othermethods) using the PRB ranking. The PRBs rank can be used to schedule acritical QCI (higher rank) compared to noncritical one (use lower rank).

2. In a CA (Carrier Aggregation) enabled environment, both cells wouldnot have a perfect overlap. (1) can be repeated for each cell andadditionally cell can be ranked based on location based on their PRBaverage performance. A higher-ranked cell becomes the preferred PDSCH(Physical Downlink Shared Channel) candidate.

(27) Sanity Suite

A sanity suite can perform tests that can be periodically run on the UE(e.g., at the end of a day), coordinated between the cloud applicationand the UE. Sanity tests can include any of a number of techniques, andhave the purpose of identifying network problems that may not have beenidentified using other techniques. For example, the sanity test may:

1) The UE, through its application (may be with alternate radio (likeWiFi), can report 1) reachability issues, 2) PCI's (Physical CellIdentifiers: quasi-unique identifiers) of the cells detected and their3) respective powers (e.g., RSSI).

2) Test: the network may configure different QCI's on the probe UE's andcheck if the QCI's are being achieved. If not, determine the difference,and if the network can correct, or further diagnosis is needed.

3) Check if cells within the BS/AP are transmitting without much anomaly(significant variations between received and expected) in power.

4) Check if there is PCI confusion/collision that is not detected. Forexample, two CBSDs (e.g., one in the home network, one in a neighboringnetwork) might have the same PCI which would cause confusion if notdetected and corrected.

(28) EN Implementation Diagram

FIG. 15 is a block diagram of an implementation of an Enterprise Network(EN) 1500 and a Cloud-Based Network Orchestration Module 1530. The EN1500 includes one or more Radio Access Networks (RANs) 1510 each locatedon a separate campus location 400. Each RAN 1510 comprises a pluralityof BS/APs 1506 that are wirelessly connected to a plurality of UEs 1512.The RANs 1510 are connected to an Operator Core Network 1520. A group ofProbe UEs 902 (e.g., see 700 in FIG. 7 ) are situated on each campuslocation 400, and may be considered as part of the RAN.

In an enterprise network deployment, the BS/APs 1506 and elements of theRAN 1510 will be located on the campus locations 400, and it is verylikely that the Core Network 1520 will be physically located at or nearone or more of the enterprise locations, especially in large or multipledeployments in the same area. However, for smaller deployments, or formultiple small deployments, it may be more cost-effective to physicallylocate the Core Network remotely from the enterprise location.

The RANs 1510 are connected to the Operator Core Network 1520 by anysuitable connection. For example, all the BS/APs 1506 in the RAN 1510may be connected to the respective RAN by any appropriate communicationsmeans, such as wire, fiber optic, and wireless radio, which is thenconnected to the Core Network 1520.

The BS/APs in the RANs 1510 are connected to, and operated andcontrolled by, the Core Network 1520. Some of the RAN services may beprovided by the Core Network 1520. The RANs 1510 provide wirelessconnections and services to a plurality of UEs on the campus locations400. A user interface (not shown) may be provided and connected to theCore Network 1510 for administration of the EN 1500.

The Core Network 1520 (which may also be called a Programmable ServiceEdge or “PSE”) provides a variety of services for the EN 1500 using aplurality of components connected to each other by any appropriatemeans. In the illustrated embodiment of FIG. 15 , the Core Network 1520includes an Automatic Configuration Server (ACS) 1521, a domain proxy1522, an MMF (Mobility Management Function) unit 1523, an SGW/PGW(Serving Gateway/Packet Data Network Gateway) unit 1524, a SelfOrganizing Network (SON) unit 1525, a KPI (Key Performance Indicator)service unit 1526, an Operations, Administration, and Maintenance (OAM)Server 1527, and units for other services.

The Core Network 1520 may be connected to a Spectrum Management Entity(SME) 1550 and a Coexistence Manager (CxM) 1552.

The Core Network 1520 is connected to the Network Orchestration module1530 by any appropriate communications means, such as a PDN 1504.Generally, the Network Orchestration Module 1530 supports the CoreNetwork 1520 and can provide additional services. The NetworkOrchestration Module 1530 may include an Administrative Service Unit1532 for remote administration of the Enterprise Network. The NetworkOrchestration Module 1530 also includes databases 1534, a MeasurementProcessing Unit 1536 that receives and processes measurements from theProbe UEs, a TDD Interference Detection Unit 1538 that manages TDDdetection, receives processed measurements and detects TDDconfigurations of neighbor networks. The Network Orchestration Module1530 may also include a Machine Learning Unit 1540, an ArtificialIntelligence unit 1542, and other components as may be necessary oruseful to support its functions.

(29) Programmable Embodiments

Some or all aspects of the invention may be implemented in hardware orsoftware, or a combination of both (e.g., programmable logic arrays).Unless otherwise specified, the algorithms included as part of theinvention are not inherently related to any particular computer or otherapparatus. In particular, various general purpose computing machines maybe used with programs written in accordance with the teachings herein,or it may be more convenient to use a special purpose computer orspecial-purpose hardware (such as integrated circuits) to performparticular functions. Thus, embodiments of the invention may beimplemented in one or more computer programs (i.e., a set ofinstructions or codes) executing on one or more programmed orprogrammable computer systems (which may be of various architectures,such as distributed, client/server, or grid) each comprising at leastone processor, at least one data storage system (which may includevolatile and non-volatile memory and/or storage elements), at least oneinput device or port, and at least one output device or port. Programinstructions or code may be applied to input data to perform thefunctions described in this disclosure and generate output information.The output information may be applied to one or more output devices inknown fashion.

Each such computer program may be implemented in any desired computerlanguage (including machine, assembly, or high-level procedural,logical, or object-oriented programming languages) to communicate with acomputer system, and may be implemented in a distributed manner in whichdifferent parts of the computation specified by the software areperformed by different computers or processors. In any case, thecomputer language may be a compiled or interpreted language. Computerprograms implementing some or all of the invention may form one or moremodules of a larger program or system of programs. Some or all of theelements of the computer program can be implemented as data structuresstored in a computer readable medium or other organized data conformingto a data model stored in a data repository.

Each such computer program may be stored on or downloaded to (forexample, by being encoded in a propagated signal and delivered over acommunication medium such as a network) a tangible, non-transitorystorage media or device (e.g., solid state memory media or devices, ormagnetic or optical media) for a period of time (e.g., the time betweenrefresh periods of a dynamic memory device, such as a dynamic RAM, orsemi-permanently or permanently), the storage media or device beingreadable by a general or special purpose programmable computer orprocessor for configuring and operating the computer or processor whenthe storage media or device is read by the computer or processor toperform the procedures described above. The inventive system may also beconsidered to be implemented as a non-transitory computer-readablestorage medium, configured with a computer program, where the storagemedium so configured causes a computer or processor to operate in aspecific or predefined manner to perform the functions described in thisdisclosure.

(30) Embodiments and Description

A number of embodiments of the invention have been described. It is tobe understood that various modifications may be made without departingfrom the spirit and scope of the invention. For example, some of thesteps described above may be order independent, and thus can beperformed in an order different from that described. Further, some ofthe steps described above may be optional. Various activities describedwith respect to the methods identified above can be executed inrepetitive, serial, and/or parallel fashion. Although the disclosedmethod and apparatus is described above in terms of various examples ofembodiments and implementations, it should be understood that theparticular features, aspects, and functionality described in one or moreof the individual embodiments are not limited in their applicability tothe particular embodiment with which they are described. Thus, thebreadth and scope of the claimed invention should not be limited by anyof the examples provided in describing the above disclosed embodiments.

Terms and phrases used in this document, and variations thereof, unlessotherwise expressly stated, should be construed as open ended as opposedto limiting. As examples of the foregoing: the term “including” shouldbe read as meaning “including, without limitation” or the like; the term“example” is used to provide examples of instances of the item indiscussion, not an exhaustive or limiting list thereof; the terms “a” or“an” should be read as meaning “at least one,” “one or more” or thelike; and adjectives such as “conventional,” “traditional,” “normal,”“standard,” “known” and terms of similar meaning should not be construedas limiting the item described to a given time period or to an itemavailable as of a given time, but instead should be read to encompassconventional, traditional, normal, or standard technologies that may beavailable or known now or at any time in the future. Likewise, wherethis document refers to technologies that would be apparent or known toone of ordinary skill in the art, such technologies encompass thoseapparent or known to the skilled artisan now or at any time in thefuture.

A group of items linked with the conjunction “and” should not be read asrequiring that each and every one of those items be present in thegrouping, but rather should be read as “and/or” unless expressly statedotherwise. Similarly, a group of items linked with the conjunction “or”should not be read as requiring mutual exclusivity among that group, butrather should also be read as “and/or” unless expressly statedotherwise. Furthermore, although items, elements or components of thedisclosed method and apparatus may be described or claimed in thesingular, the plural is contemplated to be within the scope thereofunless limitation to the singular is explicitly stated.

The presence of broadening words and phrases such as “one or more,” “atleast,” “but not limited to” or other like phrases in some instancesshall not be read to mean that the narrower case is intended or requiredin instances where such broadening phrases may be absent. The use of theterm “module” does not imply that the components or functionalitydescribed or claimed as part of the module are all configured in acommon package. Indeed, any or all of the various components of amodule, whether control logic or other components, can be combined in asingle package or separately maintained and can further be distributedin multiple groupings or packages or across multiple locations.

Additionally, the various embodiments set forth herein are describedwith the aid of block diagrams, flow charts and other illustrations. Aswill become apparent to one of ordinary skill in the art after readingthis document, the illustrated embodiments and their variousalternatives can be implemented without confinement to the illustratedexamples. For example, block diagrams and their accompanying descriptionshould not be construed as mandating a particular architecture orconfiguration.

What is claimed is:
 1. A probe device for measuring TDD interference inan Enterprise Network (EN) that has a plurality of BS/APs situated on anEN campus and utilizing a first TDD configuration for wirelesscommunications, the probe device positioned in the EN campus formeasuring TDD interference between a neighboring wireless network thatutilizes a second TDD configuration that may conflict with the first TDDconfiguration, comprising: a wireless receiver for receiving wirelesschannels; a communication link with the Enterprise Network; a frequencyscanning unit; data storage; and a TDD measurement unit for measuringTDD interference data from the neighboring network, and providing thedata to the Enterprise Network over the communication link.
 2. The probedevice of claim 1 wherein the TDD measurement unit includes an SIBMeasurement unit for receiving broadcast SIBs signals from neighboringnetworks.
 3. The probe device of claim 1 wherein the TDD measurementunit includes a UL SINR Measurement Unit.
 4. The probe device of claim 1wherein the TDD measurement unit includes a DL SINR Measurement Unit. 5.The probe device of claim 1 wherein the TDD measurement unit includes aUL RSSI Measurement Unit.
 6. The probe device of claim 1 wherein theprobe device is positioned in a fixed location in an Enterprise Networkcampus.
 7. The probe device of claim 1 wherein the probe device ismobile in an Enterprise Network campus.
 8. The probe device of claim 1wherein the wireless receiver has circuitry for receiving CBRS channelsand the frequency scanning unit has circuitry for scanning CBRSchannels.
 9. The probe device of claim 8 wherein the wireless receiverhas circuitry for receiving signals in adjacent bands, including atleast one of mid-band signals and C-band signals.
 10. The probe deviceof claim 1 wherein the probe device is a CBSD that has a built-in UE.11. The probe device of claim 1 further comprising circuitry forperforming RF environment scanning, Network Performance testing, andRadio Performance testing.
 12. In an Enterprise Network (EN) campuslocation that utilizes a TDD configuration, a method of detectinginterference from a neighboring wireless network, comprising: providinga probe device; positioning the probe device in the EN campus where itcan receive signals from the neighboring network; receiving signals fromthe neighboring network in the probe device; and determining the TDDconfiguration utilized by the neighboring network.
 13. The method ofclaim 12 wherein determining the TDD configuration of the neighboringnetwork includes receiving neighbor SIBs from the neighboring network inthe probe device.
 14. The method of claim 12 wherein determining the TDDconfiguration of the neighboring network includes measuringcommunication data in slots where TDD interference can occur betweendifferent TDD configurations.
 15. The method of claim 14 whereindetermining the TDD configuration of the neighboring network includesmeasuring UL SINR in the probe device.
 16. The method of claim 15further comprising calculating cross-correlation between two slots anddetermining TDD interference responsive to the cross-correlation. 17.The method of claim 14 wherein determining the TDD configuration of theneighboring network includes measuring DL SINR in the probe device. 18.The method of claim 17 wherein measuring the DL SINR includes observingthe HARQ feedback performance.
 19. The method of claim 14 wherein theprobe device is a BS/AP, and determining the TDD configuration of theneighboring network includes measuring UL RSSI in the probe device. 20.The method of claim 19 further comprising comparing the RSSI between twoslots.
 21. A probe device for measuring TDD interference in a wirelessCBRS Enterprise Network (EN) that has a plurality of CBSDs situated onan EN campus and utilizing a first TDD configuration for wirelesscommunications on the EN campus, a probe device positioned in the ENcampus measuring TDD interference between a neighboring wireless networkthat utilizes a second TDD configuration that has at least one slot thatconflicts with the first TDD configuration, the EN connected to anOrchestrator, comprising: a wireless receiver for receiving wirelessCBRS channels; a communication link with the Enterprise Network andOrchestrator; a frequency scanning unit for scanning CBRS channels; aTDD measurement unit for measuring TDD interference data from theneighboring network, including at least one of: an SIB Measurement unitfor receiving broadcast SIBs signals from neighboring networks, a ULSINR Measurement Unit, a DL SINR Measurement Unit, and a UL RSSIMeasurement Unit.